Objective: To study the expression and activity of matrix metalloproteinases (MMPs) MMP-2 (72-kd type IV collagenase, gelatinase A), MMP-3 (58-kd stromelysin-1), and MMP-9 (92-kd type IV collagenase, gelatinase B) and tissue inhibitors of MPs (TIMP) in patients with Guillain-Barré syndrome (GBS).

Background: MMPs are able to proteolysis of basement membranes and other matrix components, promoting transmigration of inflammatory cells from circulation to nerve tissue.

Methods: Twenty-five patients with GBS were analyzed according to the phase of the disease, i.e., progression, plateau, early recovery, and late recovery. Determinations of MMP-2, MMP-3, MMP-9, and TIMP-1 were performed using ELISA, zymography, and immunocytochemistry in circulation or peripheral nerve.

Results: MMP-9 plasma levels were increased in 67% of patients on admission and decreased from progression to late recovery (p < 0.002). During the course of GBS, MMP-9 was progressively balanced by its inhibitor TIMP-1, as assessed by the MMP-9/TIMP-1 ratio. MMP-9 and TIMP-1 plasma levels and the MMP-9/TIMP-1 ratio correlated positively with disability. MMP-2 expression was similar to controls. MMP-3 activity was not detected, and plasma levels were not different from those in controls. Positive MMP-9 immunolabeling was 51 ± 11% of circulating lymphocytes. It was observed in some endothelial cells and mononuclear cells adherent to the endothelium and close to myelinated fibers.

Conclusions: Circulating matrix metalloproteinases (MMP-9) correlates with disease severity in Guillain-Barré syndrome (GBS). MMP-9 likely represents an important molecule in the pathogenesis of GBS and therefore could represent an interesting therapeutic target.